Leading article: Mr Cameron fails to make a constructive contribution

There are plenty of locations that David Cameron might have chosen in which to broach the sensitive issue of British domestic ethnic relations.

Luton, Bradford, Birmingham, London – all would have been appropriate. Instead the Prime Minister chose Munich.

That was an especially odd decision since Germany is going through a spasm of intolerance towards its ethnic minority communities at the moment. A hysterical tract called Germany Abolishes Itself has become a bestseller. The German Chancellor, Angela Merkel, recently declared that attempts to build a multicultural society had "utterly failed". Does Mr Cameron believe that Germany, where according to a recent poll 30 per cent of the population believe the country has been "overrun by foreigners", has something to teach Britain when it comes to community relations?

Something else was troubling about the context of this speech. This was a conference on the topic of security. So by talking at length about multiculturalism and Britain's ethnic minorities, Mr Cameron was explicitly linking them with terrorism.

On the narrow subject of multiculturalism, it is essential to define terms. The word has become a bogey on the right, where it is presented as a policy intended to promote cultural ghettoisation and ethnic separation. And Mr Cameron seems to subscribe to this, arguing in his speech that "under the doctrine of state multiculturalism, we have encouraged different cultures to live separate lives, apart from each other and apart from the mainstream".

Yet this is a highly questionable definition. The policy of multiculturalism actually began life as a reaction to the widespread racism experienced by immigrant groups after the Second World War. It was an assertion that immigrants have a perfect right to celebrate their own cultures without hostility from the host community. It was thus similar in purpose to the 1965 Race Relations Act, which outlawed racial discrimination for the first time. From this perspective, to deprecate multiculturalism is to deprecate tolerance.

Mr Cameron is right that politicians have a responsibility to criticise certain malign cultural practices. More needs to be done to stamp out repugnant crimes such as female genital mutilation and "honour killings" which take place in some immigrant groups. And there is a sensible discussion to be had about the balance between accepting cultural difference and pushing integration. A reasonable debate can be had too about how best to deploy local authority resources in areas such as housing and language tuition. It is also entirely legitimate for the state to withdraw funding from groups that promote religious separatism, as Mr Cameron intends.

But too much of Mr Cameron's speech was sloppily expressed for it to be considered a constructive contribution. "When a white person holds objectionable views," suggested the Prime Minister, "we rightly condemn them. But when equally unacceptable views or practices come from someone who isn't white, we've been too cautious to stand up to them." Who does the "we" refer to here? And where is the evidence that bigotry from ethnic minorities is widely ignored? Some powerful newspapers seem to speak of little else. This is all uncomfortably reminiscent of the "dog whistle" approach of the Conservatives at the 2005 general election, whereby ostensibly reasonable language sent a covert message of support to the racist right.

The Conservative Party chair, Baroness Warsi, put her finger on something last month when she deplored the fact that Islamophobia now seems to be increasingly acceptable in polite society. Whatever his intention, Mr Cameron's speech is likely to make dinner-party bigotry, as well as other kinds, more acceptable still.